This invention is related to illumination and more particularly to self-luminous articles such as a chemiluminescent light device.
Much effort has been devoted to the development of chemical light sources as evidenced by U.S. Pat. No. 3,539,794 to Rauhut et al issued Nov. 10, 1970; U.S. Pat. No. 3,576,987 to Voight et al issued May 4, 1971; and U.S. Pat. No. 3,752,406 to McDermott et al issued Aug. 14, 1973, all of these patents being incorporated herein by reference. The disclosures of these patents specify many advantages for these chemiluminescent devices. For example, any emergency requiring the use of light is a suitable use for such a chemiluminescent device. The light is a cool light which is advantageous when the heat from electric powered light sources is not safe. The chemiluminescent device is even suitable for use underwater because no electric power is required.
One major problem exists, however, with the use of such a light source. Once the chemicals in the chemiluminescent light device are mixed in order to produce light there is no convenient way to extinguish the light produced thereby. Yet, on many occasions, it may be desirable to extinguish the light before the light-producing chemical reaction is complete. For example, in many military operations, the 3 to 24 hour illumination time is too long to be desirable, and it is necessary to extinguish the light to avoid detection. One possible solution is to make smaller devices with a short lifetime. It is possible, however, that such short-lived devices would not produce adequate light or would complicate the situation by requiring a large number of chemiluminescent light devices to be carried. It may also be undesirable to extinguish the chemiluminescent light device by hiding it away from the operation or destroying it. Both of these means require the loss of the light source to the operation. However, it may become necessary to conceal the light source after activation while retaining the ability to reuse it when necessary.
A chemiluminescent light device is required to be fragile in order to permit easy activation. But the fragility renders the device subject to premature activation and permits detection of one who happens to carry the device. Thus, it is also desirable to render the chemiluminescent light device less fragile.